llvm/unittests/Transforms/Vectorize/VPlanTestBase.h

//===- llvm/unittest/Transforms/Vectorize/VPlanTestBase.h -----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
/// This file defines a VPlanTestBase class, which provides helpers to parse
/// a LLVM IR string and create VPlans given a loop entry block.
//===----------------------------------------------------------------------===//
#ifndef LLVM_UNITTESTS_TRANSFORMS_VECTORIZE_VPLANTESTBASE_H
#define LLVM_UNITTESTS_TRANSFORMS_VECTORIZE_VPLANTESTBASE_H

#include "../lib/Transforms/Vectorize/VPlan.h"
#include "../lib/Transforms/Vectorize/VPlanHelpers.h"
#include "../lib/Transforms/Vectorize/VPlanTransforms.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/BasicAliasAnalysis.h"
#include "llvm/Analysis/IVDescriptors.h"
#include "llvm/Analysis/LoopInfo.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"

namespace llvm {

/// Helper class to create a module from an assembly string and VPlans for a
/// given loop entry block.
class VPlanTestIRBase : public testing::Test {
protected:
  DataLayout DL;

  std::unique_ptr<LLVMContext> Ctx;
  std::unique_ptr<Module> M;
  std::unique_ptr<LoopInfo> LI;
  std::unique_ptr<DominatorTree> DT;
  std::unique_ptr<AssumptionCache> AC;
  std::unique_ptr<ScalarEvolution> SE;
  std::unique_ptr<TargetLibraryInfoImpl> TLII;
  std::unique_ptr<TargetLibraryInfo> TLI;

  MapVector<PHINode *, InductionDescriptor> Inductions;

  VPlanTestIRBase()
      : DL("e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-"
           "f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:"
           "16:32:64-S128"),
        Ctx(new LLVMContext) {}

  Module &parseModule(const char *ModuleString) {
    SMDiagnostic Err;
    M = parseAssemblyString(ModuleString, Err, *Ctx);
    EXPECT_TRUE(M);
    TLII = std::make_unique<TargetLibraryInfoImpl>(M->getTargetTriple());
    TLI = std::make_unique<TargetLibraryInfo>(*TLII);
    return *M;
  }

  void doAnalysis(Function &F) {
    DT.reset(new DominatorTree(F));
    LI.reset(new LoopInfo(*DT));
    AC.reset(new AssumptionCache(F));
    SE.reset(new ScalarEvolution(F, *TLI, *AC, *DT, *LI));
  }

  /// Build the VPlan for the loop starting from \p LoopHeader.
  VPlanPtr buildVPlan(
      BasicBlock *LoopHeader,
      UncountableExitStyle Style = UncountableExitStyle::NoUncountableExit,
      bool CreateLoopRegions = true) {
    Function &F = *LoopHeader->getParent();
    assert(!verifyFunction(F) && "input function must be valid");
    doAnalysis(F);

    Loop *L = LI->getLoopFor(LoopHeader);
    PredicatedScalarEvolution PSE(*SE, *L);
    auto Plan = VPlanTransforms::buildVPlan0(L, *LI, IntegerType::get(*Ctx, 64),
                                             {}, PSE);

    if (Style != UncountableExitStyle::NoUncountableExit) {
      Inductions.clear();
      // handleEarlyExits requires induction phi recipes.
      for (PHINode &Phi : LoopHeader->phis()) {
        InductionDescriptor ID;
        if (InductionDescriptor::isInductionPHI(&Phi, L, PSE, ID))
          Inductions[&Phi] = ID;
      }
      VPlanTransforms::createHeaderPhiRecipes(
          *Plan, PSE, *L, Inductions,
          MapVector<PHINode *, RecurrenceDescriptor>(),
          SmallPtrSet<const PHINode *, 1>(), SmallPtrSet<PHINode *, 1>(),
          /*AllowReordering=*/false);
    }

    VPlanTransforms::handleEarlyExits(*Plan, Style, L, PSE, *DT, AC.get());
    VPlanTransforms::addMiddleCheck(*Plan, false);

    if (CreateLoopRegions)
      VPlanTransforms::createLoopRegions(*Plan);
    return Plan;
  }

  VPlanPtr buildVPlan0(BasicBlock *LoopHeader) {
    Function &F = *LoopHeader->getParent();
    assert(!verifyFunction(F) && "input function must be valid");
    doAnalysis(F);

    Loop *L = LI->getLoopFor(LoopHeader);
    PredicatedScalarEvolution PSE(*SE, *L);
    return VPlanTransforms::buildVPlan0(L, *LI, IntegerType::get(*Ctx, 64), {},
                                        PSE);
  }
};

class VPlanTestBase : public testing::Test {
protected:
  LLVMContext C;
  std::unique_ptr<Module> M;
  Function *F;
  BasicBlock *ScalarHeader;
  SmallVector<std::unique_ptr<VPlan>> Plans;

  VPlanTestBase() {
    M = std::make_unique<Module>("VPlanTestModule", C);
    FunctionType *FTy = FunctionType::get(Type::getVoidTy(C), false);
    F = Function::Create(FTy, GlobalValue::ExternalLinkage, "f", M.get());
    ScalarHeader = BasicBlock::Create(C, "scalar.header", F);
    UncondBrInst::Create(ScalarHeader, ScalarHeader);
  }

  VPlan &getPlan() {
    Plans.push_back(std::make_unique<VPlan>(ScalarHeader));
    VPlan &Plan = *Plans.back();
    VPValue *DefaultTC = Plan.getConstantInt(32, 1024);
    Plan.setTripCount(DefaultTC);
    return Plan;
  }
};

} // namespace llvm

#endif // LLVM_UNITTESTS_TRANSFORMS_VECTORIZE_VPLANTESTBASE_H